U.S. Pat. No. 6,165,247 discloses a pyrolysis method for the production of platinum metal, platinum alloy or platinum composite particles.
The method for the production of platinum metal particles comprises the steps of: a) generating an aerosol of droplets from a liquid wherein said liquid comprises a platinum metal precursor and wherein said droplets have a size distribution such that at least about 80 wt. % (weight percent) of said droplets have a size of from about 1 μm to about 5 μm; b) moving said droplets in a carrier gas; and c) heating said droplets to remove liquid therefrom and form platinum metal particles.
The method for the production of platinum alloy particles comprises the steps of: a) forming a liquid solution comprising a platinum metal precursor and a second metal precursor; b) generating an aerosol of droplets from said liquid solution; c) moving said droplets in a carrier gas; d) heating said droplets to remove liquid therefrom and form metal alloy particles comprising platinum metal and the second metal.
The method for the production of platinum composite particles comprises the steps of: a) forming a liquid solution comprising a platinum metal precursor and a non-metallic phase precursor; b) generating an aerosol of droplets from said liquid solution; c) moving said droplets in a carrier gas; d) heating said droplets to remove liquid therefrom and form metal composite particles comprising platinum metal and a non-metallic phase. The non-metallic phase may be a metal oxide in particular.
The platinum metal, platinum alloy or platinum composite particles can be used in the manufacture of thick film pastes which can be applied and fired to form electrodes on sensor devices, such as oxygen sensors.